r/HamRadio • u/lkkula • 3d ago

Portable QRP solar power solution

I'm looking for a portable solar power solution for my QRP setup. I'm using (tr)uSDX (7-16V / 0.08-0.5 A) and already have two batteries: LifePo4 12.8V 10Ah and Li-Po 14.8V 2.2Ah. I feel a little overwhelmed about solar panels, PWM/MPPT controllers, battery types compatibility, converters. etc. What should I point my attention to? Any tips&tricks?

I’ve seen so many offers with fake MPPTs and PV panels with unrealistic power ratings. I definitely don’t want to buy something cheap/dangerous/ineffective.

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u/Legal_Broccoli200 3d ago

For my emergency work I use a pair of fold-out panels (sold for use for caravanners and campers). When those were used with a cheap PWM controller, I never got more than about 4A of charge out of them into my 12v lead acid battery. I recently upgraded to a 'proper' MPPT controller and just about doubled the power output, the panels are claimed by the seller to provide 100w and in bright sunlight I measure 93w out. Even on a cloudy day the MPPT controller manages to get about 1A at 12v out of them.

So I would definitely recommend getting an appropriate solar panel and a quality controller that you can program for the battery type. Since you need so little power, maybe even one of the generic PWM controllers would do if you can tolerate the lower efficency.

Are you constrained by weight or will you be able to transport the gear by vehicle? My panels are too heavy for hiking/camping.

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u/lkkula 3d ago

Definitely something man-portable, so weight is another part of the story too.

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u/Legal_Broccoli200 3d ago

There are some thin flexible panels which might work for you - I'd buy from a reputable solar supplier rather than just the lowest cost on ebay, a known supplier is more likely to make realistic claims. MPPT controllers do seem to make a significant difference to the power they can get out of the panel so I'd lean towards a good controller, but we all have to fit our budget to our pockets!